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CO-9 - Denial Journal
CARC CO — Contractual Obligation

CO-9

Diagnosis inconsistent with the patient's age

What This Code Means

The diagnosis code billed is not clinically consistent with the patient’s age.

Common Causes

  • Pediatric- or adult-specific ICD-10 code used for the wrong age group
  • Data entry error in date of birth

How to Resolve or Appeal

  1. Confirm patient date of birth on the claim
  2. Verify the diagnosis code is age-appropriate; correct and resubmit

More Denial Codes to Check

CARC CO-148 RARC MA76 RARC M51 Missing/incomplete/invalid procedure code(s) RARC N77 RARC M76 Missing/incomplete/invalid diagnosis or condition RARC MA27 RARC M15 Separately billed services bundled as components of the same procedure CARC A1 Claim/service denied — generic code, use only when no more specific code applies

Educational reference only — not medical or legal advice. Always confirm code usage and appeal rights with the specific payer.

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